| Name the four different type of keyboards and give a small description for each | QWERTY
Names because of the first line of key is qwerty
Ergonomic
A keyboard designed to prevent RSI( Repetetive strain injury)
Concept keyboard
Keys are printed onto a thin sheet of plastic
Normally used in pubic places such as self service restaurants, ATMs and in appliances such as washing machines and microwaves
Easier to clean
Easier to use since they keys can be different shapes, color, sizes
Braille keyboard
A keyboard used by blind people |
| What is a 2D scanner ? | A 2D scanner converts documents into 2D images that input to a computer |
| Give two applications of 2D scanners | 1)Scanning passport images for facial recognition
The passport image is scanned in and then compared with a digital image of the passenger taken by a digital camera.
2) Updating passport information on at the airport using optical character recognition |
| What is a 3D scanner and state two places where it is used? | Medical imaging using xray
MRI scanners using radio scanners |
| What is a barcode ? | Set of line of different thickness that represents different numbers |
| What are the applications of barcode? | Supermarket billing
Recording attendance in a company |
| What are the contents of a barcode reader? | Country of orgin
Manufactures code
Serial number |
| What is a pointing device? | A device used to move the pointer on the screen |
| Name four pointing devices | Mouse
Joystick
Tracker ball
Touch pad |
| Give one disadvantages of the mouse | Takes space to operate |
| Give two advantages of joystick | Takes less space to operate
Faster to move |
| Where are joysticks used ? | Mainly in gaming |
| Give an advantage of tracker ball | Takes less space than mouse |
| Give two places where tracking ball is used | Wheelchairs
Operating CCTV cameras |
| Give an advantage of the touch pad | Takes less space to operate |
| Where are microphones used? | Online conferences |
| What is voice recognition, how does it work, where is it used? | A person is recognized by his voices when he speaks into a microphone
It works by converting a recording of person's voice into a digital form and stores it into the the computer, when someone speaks into the microphone another digital pattern is created which compared to the stored pattern.
Security systems which require to identify the person |
| What is speech recognition? | A computer recognizes words spoken into the microphone and performs tasks according to the word spoken |
| What are the drawbacks of speech recognition? | Background noises will confuse the system
Different people will have different accents\punctuations
Recognition is slow |
| Where is speech recognition used? | For disabled people
Operating a mobile device
Dictating words to a word processor |
| How does speech recognition work? | Each word spoken into the microphone is broken down into its individual phonems, then a dictionary of phonems is searched for the same combination of phonems and word is recognized |
| What is analog data? Give examples | Data which gradually changes from one state to another
Sounds
Temperature
Speed |
| What is digital data? Give an example | Data which changes from one state to another without any intermediate stages
Switch |
| What is a monitoring system? Explain how it works | Measures a variable in its enviroment and compares it with the range of stored values and if it is outside the range it will warn the user
Sensors send readings to the analog to digital converter at regular intervals
The ADC converts the analog signals to digital so that it can be processed by the microprocessor and then sends it to the microprocessor
The microprocessor compares the readings to the maximum and minimum stored value
If the reading outside the acceptable range a warning message is sent or an alarm is activated |
| Give three places where monitoring systems are used | Monitoring heart rate of a patient in a hospital
Temperature level in car engine
Burglar alarm |
| What is a control system? Explain how it works | Measure a variable in its enviroment and takes action to maintain the variable in the acceptable range
The sensor send readings to the analog to digital converter at regular intervals
The ADC converts the analog signals to digital so that it can be processed by the microprocessor and sends it to the microprocessor
The microprocessor compares reading with the maximum and minimum value
If the readings are within the range a signal is sent through the digital to analog converter to switch off the actuator
If the readings are outside the acceptable range a signal is sent through the digital to analog converter to switch on the actuator |
| What is an actuator? | A computer controlled device which can change its enviroment |
| What is a MIDI file? | Musical Instrument Digital Interface
A MIDI file contains instructions on how to play music
MIDI file is read by sequencer software on the computer
Computer is connected to a MIDI interface(Device)
MIDI interface is connected to music instruments such as electric drum, electrical guitar
The sequencer software translates each MIDI instructions to musical instrument, processes and sends it to the instruments through the MIDI interface
Musical instrument plays the music
Can connect up to 16 channels (Devcies) |
| What are the advantages of MIDI files over mp3 | Smaller file
Easier to edit |
| What are the disadvantages of MIDI files over mp3 | Special hardware |
| What are the advantages of barcodes in supermarket ? | To the company
Automatic stock control
Less cashiers so saving money
Less errors in billing
To the customer
Less waiting time
More detailed |
| What is QR (Quick Response) code? What are the items stored in QR? | A set of black dots on a white background, which can store up to 7000 characters
URL
Phone number
Address of the vendor |
| What are the advantages of QR codes? | A special reader is not required (Any digital device with a camera is suitable)
Larger capacity than barcodes
Scanning can be done from a distance |
